She was sitting on his big cock, riding him hard but trying not to make large waves. She winked at us and actually blurted out a soft "Aaaah," as he o...viously had blown his cum inside her and brought her off by doing so. We all laughed and pretended to be too drunk to admit that we'd had a unique foursome.Anyway, after that fantastic day in the clinic, I found out just how much Lynn loved to suck cock. If possible we'd head out to lunch separately, then meet up in a parking garage or at a rest. “Hi Steve” I said “Great to meet you”“I have to run a some errands for a few hours” he said. “Here’s my house key and address. Let yourself in and I’ll catch up with you there around lunchtime”. He handed me a key with a keyring that had an address on it. He was obviously prepared. “I’ll see you later” he said, and he turned to leave.I took the initiative and stopped him. “Steve” I said “I’m sorry, but I have to ask. Is there anything in particular you want from me that would make you happy. I and my sister were very close from our childhood even after her marriage I got the first priority in most of the things. She will usually kiss me on my forehead, rarely on my lips which would make me horny. She never had bad intentions on me and my sister who is 8 years elder to me is mother of two kids but no one can ever say so but. She is very much involved in maintaing her body and fair complexion, sexy sexy round breasts, flat belly with little fat lingering and a wide hip. Due to our. Her knees parted, raising the skirt and showing me more of her smooth thighs.I gulped at her blatant innuendo. "No, Julie, I can’t…" Don't you find me attractive, sir?" she pouted, tossing her blonde hair. "I’ve noticed you looking at me. A lot." She stretched her shoulders back, pulling the thin fabric of her top tightly over her braless nipples. "And you did touch my leg last week."Shit. I thought I had been fairly discreet with my glances at her tits and legs during our weekly tutorial.